Efficacy of clarithromycin in preventing viridans streptococcal bacteremia following autologous stem cell transplantation.

ABSTRACT

BACKGROUND: In a study involving 200 patients, we previously found that 17.5% of patients developed viridans streptococcal (VS) bacteremia following autologous peripheral blood stem cell transplantation (aPBSCT) when ciprofloxacin or ciprofloxacin plus ampicillin was used for prophylaxis. PATIENTS AND METHODS: A retrospective evaluation of 100 consecutive recipients of aPBSCT was conducted to ascertain the incidence and outcome of VS bacteremia when a combination of ciprofLoxacin and clarithromycin was utilized for antimicrobiaL prophylaxis following transplantation. The 200 patients from our previous study, in which ciprofloxacin alone or ciprofloxacin with ampicillin was used for prophylaxis, were combined with the current group for the purpose of statistical analysis. RESULTS: Streptococcus mitis was isolated from the blood of five individuals at a median of 5 days following stem cell infusion. Each of these patients was neutropenic and presented with fever. Three isolates demonstrated intermediate resistance to macrolides in vitro. However, all episodes of bacteremia were treated successfully with systemic antibiotic therapy. CONCLUSION: Age, duration of neutropenia, type of underlying malignancy and type of conditioning chemotherapy regimen failed to have a significant impact on subsequent VS bacteremia. Only female sex and use of ciprofloxacin without clarithromycin as antimicrobiaL prophyLaxis predicted a significantly increased risk of VS bacteremia in both univariate and Logistic regression analyses.